AQA PSYCHOLOGY- BIOPSYCH EXAM QUESTIONS AND ANSWERS WITH COMPLETE SOLUTIONS GRADED A++

AQA PSYCHOLOGY- BIOPSYCH EXAM QUESTIONS AND ANSWERS WITH COMPLETE SOLUTIONS GRADED A++ Divisions of the Nervous System Central Nervous System (CNS): Involves both brain and the spinal cord. Brain is the centre of all conscious awareness. The brain's outer layer is the cerebral cortex and is highly developed in humans. Brain is divided into two hemispheres. Spinal cord transmits messages to and from the brain and also to the PNS. Peripheral Nervous System (PNS): Made up of the nerves outside the CNS, allowing sensory information to be received from the whole body, and motor control of the body. Peripheral Nervous System (PNS): Somatic nervous system. Somatic nervous system: -Made up of nerves emerging from the brain and the spine. Nerves contain both sensory neurons and motor neurons. -Sensory relay messages to the CNS and motor relay info from CNS to the body. -Somatic nervous system allows your CNS to receive sensory information from around the body and to make conscious muscle movements. -It is involved with reflex actions. It is the somatic nervous system nerves in the spinal cord which generates the command to pull away from a hot stove. Peripheral Nervous System (PNS): Autonomic nervous system. - Controls automatic processes. -Transmits information to and from internal organs to sustain essential processes required for life. -This include involuntary movements (startle response), heartbeat and breathing -Is made up entirely of motor pathways -Commands come from the brain stem (at the bottom of the brain where it joins the spine) -It has two parts - the sympathetic and the parasympathetic ANS. These work in opposition to each other, with the sympathetic ANS stimulating organs and tissues and the parasympathetic ANS inhibiting them. The structure and function of sensory, relay and motor neurons: Neurons. Neurons are cells that are specialised to carry neural information throughout the body. Neurons can be one of three types. They typically consist of: -A cell body (the control centre of the neuron) -Dendrites (at one end of the neuron, receiving signals from other neurons or from sensory receptors) -And an axon (carries the impulse to the axon terminal). The structure and function of sensory, relay and motor neurons: Sensory neurons: Sensory neurons: · Carry nerve impulses from sensory receptors found in the Peripheral Nervous System to the CNS. These receptors are e.g. in the eyes, ears, tongue and skin · Some neurons carry information from these receptors to the brain, which translates that information into sensations · Some neurons terminate in the spinal cord, which produces a reflex action more quickly as the information does not have to travel all the way to the brain The structure and function of sensory, relay and motor neurons: Relay neurons: Relay neurons: · These neurons go in between the sensory inputs (from the PNS to the CNS) and the motor output (from the CNS back to the PNS to control muscles and glands) · Relay neurons therefore allow sensory and motor neurons to communicate · These can be found only in the brain and spinal cord. Relay neurons in the brain also allow for cognitive processes and decision making The structure and function of sensory, relay and motor neurons: Motor neurons: Motor neurons: · Motor neurons start in the CNS, but send their axons outside the CNS to control muscles and glands. · Motor neurons form synapses with muscles and control their contractions. When stimulated the motor neuron releases neurotransmitters that binds to receptors on the muscle and trigger a response of muscle movement The strength of the muscle contraction depends on the rate of firing of the axons of motor neurons The structure and function of sensory, relay and motor neurons: The process of synaptic transmission: The process of synaptic transmission: 1. An action potential travels down the axon of a neuron 2. This action potential arrives at the end of the pre-synaptic terminal, but cannot cross the synaptic gap separating it from the dendrite of the next neuron 3. The whole structure of the synapse involves the end of the presynaptic neuron, the membrane of the postsynaptic neuron, and the gap in between them. 4. The presynaptic neuron releases vesicles into the synaptic gap. These vesicles contain chemical messengers known as neurotransmitters. 5. These released neurotransmitters diffuse across the synaptic gap to the membrane of the postsynaptic neuron. They can either be excitatory (stimulate firing) or inhibitory (making firing less likely) - see the next box Neurotransmitters are either excitatory or inhibitory Neurotransmitters are either excitatory or inhibitory The neurotransmitters that are released into the synaptic gap can have one of two actions: 1) Excitatory neurotransmitters include acetylcholine and noradrenaline. These make the postsynaptic neuron more likely to fire (because they excite the postsynaptic neuron). 2) Inhibitory neurotransmitters include serotonin and GABA. These make the postsynaptic neuron less likely to fire (inhibit means to stop something). What follows is the process of summation. Summation The axons of multiple presynaptic neurons connect to the dendrites of a postsynaptic neuron. This means the postsynaptic neuron can receive information from multiple neurons in the form of different neurotransmitters.